A preliminary investigation was undertaken in a Blood Bank regarding the selective merits of indirect immunofluorescent serie reactions for diagnosis of malaria, in donors apt to transmit the infection through blood samples collected for hemotherapy. The study consisted of performing the above tests on 192 random individuais frorn whom blood was taken for this purpose. Comparison of laboratory results with Information provided by the individuais in question shows good especificity along with non-integral sensitivity. The authors stress the convenience of more detailed and thorough investigations in this field for a better evaluation of the data obtained and analyzed so far.